One of the most disturbing criminal cases in modern French history is about to be relived in raw and harrowing detail.

A film chronicling the last days of Ilan Halimi, a young Parisian Jew murdered by a self-proclaimed Islamist, was premiered in France on Wednesday night.

It has already received serious acclaim but will shock filmgoers: the director, Alexandre Arcady, heard people say at pre-premier screenings: “I am ashamed to say I’d forgotten him.”

Mr Arcady’s film, 24 jours: la vérité sur l’affaire Ilan Halimi (“24 Days: the truth about the Ilan Hamili affair”), was inspired by a book with a similar title written by the victim’s mother, Ruth.

Halimi, 23, was kidnapped and tortured for 24 days by a gang led by Youssouf Fofana, the extraordinarily cruel, Paris-born fifth of seven children of immigrants from the Ivory Coast.

When found naked, handcuffed and bound to a tree near a railway station in February, 2006, Halimi’s body had been horribly mutilated. Incredibly still alive, he died on the way to hospital.

Halimi was targeted because he was Jewish, falsely assumed to come from a prosperous family. A 450,000-euro ransom was demanded. But he was a 1,200 euro-a-month assistant in a mobile phone shop, his family of modest means.

“We haven’t seen acts of this kind since the Holocaust,” his mother said after the murder eight years ago.

Fofana, 28 when convicted three years later, was given life imprisonment with a 22-year minimum. Some of his 26 accomplices, jailed with him, are already free.

Among glowing reviews of the film, an article in Le Journal du Dimanche (JDD) describes a tragic, real-life thriller that is “relentless, distressing and without hatred”. For Le Nouvel Observateur, he succeeds brilliantly in his desire to make the tragedy of Hamili “a duty to remember”.

Mr Arcady remembers how French police, investigating the crime just six months after riots that began in Muslim-dominated suburbs swept the nation, at first denied any antisemitic aspect. “The mindset was not to pour oil on the fire.”

He is depressed by the hatred that persists on French streets: the chant “Jew, France is not for you” was heard during an anti-government demonstration on the eve of International Holocaust Memorial Day in January.

“Ilan’s death reflects a sick society,” Mr Arcady told the French newspaper, Le Journal du Dimanche, echoing the thoughts of one of the lawyers involved in the original trial.

Describing the estate where the crime occurred, he added: “Among 500 families living there, some knew what happened but no one spoke… My film is a warning against indifference.”